Questionable research practices, the importance of preregistration, and the flaws of the peer review system were already familiar topics to me. However, the talk on Open Access publishing provided some very interesting information and helped me understand my own discomfort in paying to openly publish my research. Apparently, charging huge fees for Open Access publishing can be an extremely lucrative business model. There are many online articles on the issues surrounding such business models and their effects on the scientific literature. For example, you can start reading here, here, or here (Dutch article).